<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>物理像素比</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        
        div{
            width: 300px;
            height: 300px;
            background-color: pink;
        }

        /* 1.物理像素 就是我们说的分辨率 IPhone8的物理像素是 750 */
        /* 2.在IPhone8里面 1px 开发像素 = 2个物理像素 */
    </style>
</head>
<body>
    <div></div>
</body>
</html>